Mobile carriers, such as carts, are equipped with conventional caster brake devices to prevent the mobile carriers from moving when inadvertently pushed or hit. The conventional caster brake devices each include a lock mechanism adapted to be mounted on an axle of a mobile carrier to lock the axle, thereby preventing the axle from rotating. Therefore, the conventional caster brake devices can brake the mobile carriers.
For instance, a conventional caster brake device is for use with a mobile carrier whose casters are each provided in the form of a round gear. The conventional caster brake device comprises movable gears which mesh with the round gears, respectively. Mobile carrier users move the movable gears to control the extent to which the casters mesh with the movable gears, thereby locking and unlocking the conventional caster brake device.
Considering that mobile carriers for use in hypermarkets and supermarkets are likely to collide with each other and mobile carrier users have to lock and unlock the caster brake devices frequently, the aforesaid conventional caster brake device has two drawbacks described below.
First, the gears are readily stripped, because the meshing gears must be small enough to enable the lightweight mobile carriers to move quickly and adeptly.
Second, with the meshing gears being subjected to tangential forces, the conventional caster brake device is likely to fail for reasons below. Public use of the mobile carriers does not preclude the chance that users will improperly operate the gears, for example, starting to mesh the gears while the gears are still rotating, thereby leading to bad consequences, including tilted gears, deformed gears, damaged axles, and failure to unlock.